Have had this for a little while and been trying to get the barrel cleaned. The beginnings of the rifling at the throat have what looks like lumps on the top of the lands. Hoppe's won't even touch it even letting it soak and using 8mm brushes to try a scrub it out. I'm thinking the lumps are cupro nickle from bullets made out of the same material. It dates from 1915 according to the serial number so that type of bullet metal was in use around that time. Anyone have suggestions for a solvent that would remove the cupro nickle lumps?. As always your comments and suggestions are greatly appreciated. Thanks,Frank